1. Field of the Invention
This invention relates to a method of determining whether or not a drug administered to an animal is absorbed into the body and distributed in the blood.
2. Description of the Prior Art
Drugs are applied orally, intravenously, intraperitoneally, rectally, intramuscularly, subcutaneously or by inhalation in the form of internal preparations, or by percutaneous absorption in the form of external preparations, and a proper method of administration is selected case by case depending on the type of drug and the kind of disease to be treated.
In any of these administration methods, it is important to make clear the actual behavior of the applied drug in living bodies, such as absorption, distribution, metabolism and excretion, in order to prove its efficacy.
Distribution of a drug absorbed in animal bodies is now measured by analysis of that drug contained int he blood or tissues through a physicochemical method, such as high-performance liquid chromatography, or by the use of drug labelled with a radioisotope.
However, some drugs containing substances extracted by a definite method from a plant or an animal treated in a specific way beforehand (like biological, natural drug and crude-drug preparations) often comprise a great variety of active components and hence exhibit the drug action as a result of synthetic effects of these components. If one tries to investigate the actual behavior of such a drug in living bodies, for example, by oral administration, by a conventional analytical method, the behavior of each of these components including unknown or trace substances must be determined. This can hardly be effected by the techniques presently available, and there has been a demand for a new method that can determine the behavior of such drugs simply and correctly.
This invention is to meet this demand.